1. Field of the Invention
The present invention relates to a booster seat and, more specifically, to a booster seat having armrests and a seat member. The booster seat is capable of changing the distance between the armrests according to the height of the support portion of the seat member.
2. Description of the Related Art
A booster seat is used on a vehicle to seat a child taller than babies and shorter than adults, such as a schoolchild (hereinafter referred to simply as xe2x80x9cchildxe2x80x9d), at a proper level on the seat of the vehicle.
Generally, a seat belt cannot be properly put around a child if the child is seated on the seat of a vehicle. Therefore, a booster seat is placed on the seat of the vehicle and the child is seated on the booster seat so that the apparent height of the child is great enough to put the seat belt around the child.
A known booster seat is provided with armrests that can be moved to adjust the width of the support portion of a seat member according to the build of a child to be seated on the booster seat.
In this known booster seat, the height of the support portion remains unchanged regardless of the width thereof. Therefore the booster seat is narrow to a tall child and is unable to hold a short child steady.
The present invention has been made in view of such a problem and it is therefore an object of the present invention to provide a booster seat having armrests and a seat member, in which the distance between the armrests can be changed according to the height of the support portion of the seat member.
According to the present invention, a booster seat comprises a base to be mounted on a seat of a vehicle; a seat member placed on the base and having a support portion; a pair of armrests disposed on opposite sides of the seat member, respectively; a seat height adjusting mechanism capable of vertically moving the seat member relative to the base to adjust the height of the support portion of the seat member, and an armrest adjusting mechanism capable of adjusting the distance between the armrests according to the vertical movement of the seat member by the seat height adjusting mechanism. The distance between the armrests is decreased when the height of the support portion of the seat member is increased, and is increased when the height of the support portion of the seat member is decreased.
In the booster seat according to the present invention, it is preferable that the seat height adjusting mechanism comprises a plurality of wedge-shaped blocks disposed between the base and the seat member, tapered from the opposite sides of the support portion toward the middle of the support portion, respectively, and each having an upper surface serving as a first slope. A bottom part of the seat member faces the plurality of wedge-shaped blocks and has a second slope corresponding to the first slopes. The seat member can be moved vertically relative to the base by the cooperative action of the first slopes of the plurality of wedge-shaped blocks and the second slope of the seat member when the plurality of wedge-shaped blocks are moved in directions along the width of the support portion. It is also preferable that the armrest adjusting mechanism includes a pair of side members extended along the opposite sides of the support portion of the seat member on the base, connected to the outer ends of the plurality of wedge-shaped blocks, respectively, and is provided with the armrests, respectively. The distance between the armrests can be adjusted by moving the side members together with the plurality of wedge-shaped blocks on the base in a direction along the width of the support portion.
In the booster seat according to the present invention, it is preferable that the seat height adjusting mechanism includes an operating bar provided with pins extending along the width of the support portion of the seat member. The base and the seat member are provided with longitudinal slots capable of receiving the pins of the operating bar, respectively, and are inclined relative to each other. The seat member can be moved vertically relative to the base by the cooperative action of the pins of the operating bar and the slots of the base and the seat member when the operating bar is moved longitudinally on the base in a state where the seat member is able to move only vertically relative to the base. It is also preferable that the armrest adjusting mechanism includes a pair of bearing portions formed on the base, each for pivotally supporting one end of each armrest. The seat member is provided with a pair of openings in which the armrests are inserted, respectively. The armrests turn in a plane perpendicular to a direction along the length of the support portion as the seat member is moved vertically relative to the base so that the distance between the armrests is adjusted.
According to the present invention, the seat height adjusting mechanism moves the seat member vertically relative to the base to adjust the height of the support portion of the seat member, and the armrest adjusting mechanism moves the armrests according to the vertical movement of the seat member by the seat height adjusting mechanism to adjust the distance between the armrests. Thus, the distance between the armrests can be automatically adjusted according to the adjustment of the height of the support portion of the seat member. When the height of the support portion is decreased for a tall child, the distance between the armrests increases, so that the tall child can be comfortably seated on the booster seat. When the height of the support portion is increased for a short child, the distance between the armrests decreases, so that the short child can be seated on the booster seat in a steady position.
According to the present invention, when the seat member is moved vertically relative to the base by the cooperative action of the seat member and the plurality of wedge-shaped blocks capable of moving along the width of the support portion, and the distance between the armrests is adjusted by moving the pair of side members in coordination with the movement of the wedge-shaped blocks, the seat member can be vertically moved and the distance between the armrests can be adjusted by mechanical mechanisms. Thus, the booster seat is simple in construction and capable of functioning with reliability.
According to the present invention, when the seat member is moved vertically relative to the base by the cooperative action of the pins of the operating bar that move along the length of the support portion on the base, and the slots of the base and the seat member, and the distance between the armrests is adjusted by turning the armrests in coordination with the vertical movement of the seat member relative to the base, the operations for vertically moving the seat member and adjusting the distance between the armrests can be very easily achieved, and the seat member can be vertically moved and the distance between the armrests can be adjusted by mechanical mechanisms. Thus, the booster seat is simple in construction and capable of functioning with reliability.